For one, I think the stigma against curse words is slowly being lifted. Not only can you say "bitch" on TV, but you can also say "fuck" in places where it previously would have been considered inappropriate. Maybe it's because I live in New York, but I can hear someone say "fuck" in almost any public space and not be offended or taken off guard in the slightest. People in my office, a professional space, often employ curse words. My professors use them. People on the subway use them. My barista at Starbucks uses them. Curse words do not necessarily make you seem uneducated anymore. They are not relegated to just the vernacular of the poor. Instead, they've seemed to cross both economic and gender lines in order to make our speech that much more fucking awesome.
I also think, as women gain more power in our society (Think: Hillary running for President, Nancy Pelosi as the Speaker of the House, Britney Spears as the most famous person in the country), we are less afraid of sounding like "men" and more afraid of sounding weak. Thus, the introduction of "fuck" and "shit" and "damn" into everyday vocabulary.
I, for one, am happy with this change. I had the foulest mouth as a little girl, and that hasn't really gone away. So if women are beginning to side with me in an attempt to say FUCK YOU to vocabulary standards, then of course, I think that's the shit.